Polyurethane – Insulating material
The extraordinary insulation properties of sandwich panels are largely down to their cores, i.e. the inner material that is protected by the stainless steel or aluminium outer sheathing of the stainless. Polyurethane is one of these core materials - a synthetic resin, which was developed in the thirties by Otto Bayer and his research group for I.G. Colors. Foams can be produced particularly well from polyurethane. Due to its exceptionally good insulation properties, polyurethane is therefore used as a core material for sandwich panels.
However, not only sandwich-panel cores, but also everyday items are made from the synthetic resin. Everyone who has ever done the washing up has, for example, come across the colorful household sponges made of soft "PUR foam".
Picture of household sponges made of polyurethane, the core material for sandwich panels